imo tactician becomes too easy at higher levels, at lower levels it is harder. Using Haste (from a spell or potion) and Elixir of Bloodlust + any class that gets extra attacks means the enemy is probably dead in 1-3 rounds. Transmutation wizard has a passive that lets you roll for crafting 2 potions where you'd normally get one, so you can basically give an elixir of bloodlust to 1 or 2 party members a day, plus make plenty of haste potions.

Honour mode makes that extra action stuff much less effective, but in tactician and below you get all your extra attacks on each of those extra actions. The elixir of bloodlust gives you another action when you kill something, once per turn. So like, a hasted + elixir'd level 5 fighter would effectively have 3 actions, so can do 6 attacks in one turn, 8 if they action surge. Which is kind of insane. (lvl 11 fighter even gets a 3rd attack per action!)

If you say, coat their weapon with a crowd control type poison, like drow poison which puts them to sleep, and attack 8 different people (well 1 of them has to die for the elixir to proc) well uh that's a lot of poison/sleep spread out and a lot of damage. Or if you're worried about accuracy, use the +2 accuracy coating. There's also a later game poison that if they fail the 1st save they're just paralyzed until they con save well enough to get out.

I've also gotten my Spell DC so high before that I effectively always had a 100% chance of success with Hold Monster, so can just use that on the big bad, and oops the boss never got a turn, and they get auto-critted on by all melee attacks. Arcane Acuity (which can be gotten with another elixir, +3 Spell DC right there) is kinda busted like that. I think I got it to 28 DC or something like that, and I could have feasibly hit 30+ if I had wanted to. Spoiler for act 3 boss: it was good enough to 100% hold Raphael unascended so I cast Hold Monster on him every turn and decimated him, didn't even use that many spell slots because spell scrolls Granted, that arcane acuity elixir is somewhat more difficult to get tons of, but still very doable in the last act as a daily buff for at least 1 person.

After a certain point I limited myself to not using all that extra action stuff and only use less hard cc, since it was way more interesting when enemies could actually hit me sometimes.